Cruise control retrofit - 940 - speed signal wire

[tofufi]

Hi folks

Trying to retrofit cruise control to my brother's 940 lpt, 1995.

All is in and fitted, but it doesn't work.

My first suspicion is that it isn't getting a speed signal.

Removed the speedometer, and it has this:



Am I right in thinking that the cruise control gets the signal from the D terminal? (This is where the white and purple wire is connected at the moment).

The wiring from the cruise ECU has a yellow wire going into the loom, but I can't see a single spade anywhere to attach to the speedometer. Does anyone know where it pops out of the loom?

Cheers

[tofufi]

As a quick update, looking at the 1995 wiring diagram it seems it should be the green/orange wire from terminal 13 which goes to the speedometer.

Doing a continuity check, there is continuity between this wire at the cruise control ECU and the speedometer terminal D. So perhaps this isn't the issue

[tofufi]

All solved now - turns out the indicator switch had a broken wire

It turns out the Volvo wiring diagram for the '95 model shows the wrong colour wire to the speedometer

[360beast]

Brilliant, glad you've got it all sorted!

[Clan]

Originally Posted by tofufi

All solved now - turns out the indicator switch had a broken wire

It turns out the Volvo wiring diagram for the '95 model shows the wrong colour wire to the speedometer

It could be that yours is actually a 1994 or 1996 ... one of the VIN characters determines the model year .

[griston64]

Originally Posted by tofufi

All solved now - turns out the indicator switch had a broken wire

It turns out the Volvo wiring diagram for the '95 model shows the wrong colour wire to the speedometer

Also glad it's all sorted seeing as I sold it to you

[TonyS9]

Yeah I connected my MPGuino to the speedo double terminal.

[tofufi]

Originally Posted by TonyS9

Yeah I connected my MPGuino to the speedo double terminal.

While I think of it, would it be possible to fit cruise control to a 340 using an appropriate loom and the speedometer inserts you sell?

I think the speedo on the 940 has a 48 toothed ring, whereas the 340 speedo insert probably only switches twice per revolution?

I also don't know if the cruise receives a signal that is modified by the speedometer?

[TonyS9]

Originally Posted by tofufi

While I think of it, would it be possible to fit cruise control to a 340 using an appropriate loom and the speedometer inserts you sell?

I think the speedo on the 940 has a 48 toothed ring, whereas the 340 speedo insert probably only switches twice per revolution?

I also don't know if the cruise receives a signal that is modified by the speedometer?

Yes it would be possible to make with an aftermarket system that was programmable, you just have to ensure the system has an appropriate feedback delay or damping. You basically get 2x wheel rpm frequency. The 48 tooth ring is really for ABS use where you need a higher resolution.

[slo432]

Hey, I’ve recently bought a 97’ 945 and I’m getting it ready to take on a long journey across EU to Portugal. I’m interesting in getting CC set up and installed. Could I come to you to get more info about the install? I’m new to working on cars and electronics are pain